Thermostat system



F. THORNTON, JR.

' THERMOSTAT SYSTEM.

APPLICATION FILED 0612,1914.

33 139 V Patented Mar. 30, 1920.

a 15 as i r I I k as [a i I x WITNESSES: INVENTOR Fm/7K 7770177700.]7.

. ATTORNEY UNITED STATES PATENT OFFICE.

FRANK THORNTON, JR., PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENN- SYLVAN IA.

THERMOSTAT SYSTEM.

Specification of Letters Patent. Patented )Iar. 30, 1920.

Application filed October 2, 1914. Serial No. 864,551.

To all whom it may concern.-

Be it known that I, F RANK THORNTON, J 1 a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Thermostat Systems, of which the following is a specification.

My invention relates to thermostatic systems for electric circuit control, and it has for its object to provide a system of the character indicated thatshall be simple in construction and arrangement, rapid and certain in operation, and capable of being operated without the use of an auxiliary source of current.

The regulation of electric circuits for the purpose of obtaining constant temperatures is frequently accomplished by the use ofthermostatic expansion members. Relative motion between two points is caused by the unequal expansion and contraction of-the different materials composing the thermostat, and the rate of this motion, which is approximately in direct proportion to the rate of temperature'change, is very slow, under ordinary circumstances. If the movement of the thermostat is relied upon to close and to separate electric contact members, destructive arcslare likely to be drawn when the contact members are slowly separated, and, for this reason, it has heretofore been necessary to dispose the thermostatically operated contact members in a separately-encrgized control circuit carrying-current at very low voltage.

According to my present invention, I provide a control circuit which includes a thermostat and which is energized directly from the main supply circuit, and I avoid destructive arcing between the contact members operated by the thermostat by providing separate means for interrupting the control circuit while the contact members are in engagement. so that the thermostat oper ates to close the control circuit, but never inter'rupts it.

For a better understanding of my invention, reference may now be had tothe accompanying drawing, in which Figure 1 is a diagrammatic View showing a control sys tem embodying my invention, and Fig. 2 is a fragmentary diagrammatic view showing a portion of the system the relay 6 is opened and permitted to fiow when the relay is closed. The relay 6' is operated by means of-a solenoid coil 7, the terminals of which are connected across the main conductors 2 and 8 by means of conductors 8 and 9, the conductor 9 being provided with spaced contact members 10 and -11 which are adapted to be connected by a relay contact member 12. The contact member 12 is secured to a swinging support 13, which is pivoted at 14 and which carries, at its end opposite to the contact member 12, two spaced contact members 15 and 16.

The support 13 may either be of insulating material or it may be provided with insulating means for supporting the various contact members which it carries. Pivoted at 14. and movable with the swinging support 13, is an armature core 17 that is oscillate between the opposed pole pieces 18 and 19'of an electromagnet 20. The core 17 is surrounded by a coil 21. the terminals 22 and 23 of which are connected to the contact members 15 and 16, respectively. Disposed at one side of the support 13, near its upper end, are stationary contact members 24 and 25 which are adapted to be engaged by the contact members 15 and 16, respectively. Similar stationary contact members 26 and 27 are disposed opposite the contact members 24 and 25. The arrangement of the contact members is such that, when the parts are in the positions shown in the drawing, the contact members 15 and 16 engage the contact members 24 and 25, thus establishing electric connection between the contact members 24 and 25 through the armature coil 21, and that the contact members 11 and 12 are disconnected. When the support 13 swings in a counter-clockwise direction about the pivot 14, the contact members 15 and 16 will adapted to and 26 are connected to each other by means of a conductor 28, and the conductor '1 28 is connected to the main conductor 3 by means of a conductor 29 in which is inserted, in series relation, the coils 30 and 31 of the electromagnet 20.

The contact members 24 and 27 are respectively connected to adjustable contact members 32 and .33, between which is disposed the free end of a thermostatic element 34, which, as shown, is a bimetallic couple. The thermostat 34 is provided, near its free end, with contact members 35 and 36, which are adapted to engage the adjustable contact members 32 and 33, respectively, and is secured, at its other end, to a terminal block 37 which is connected, by means of a conductor 38, to the main supply conductor 2. Other types of thermostats may be readily substituted for the bimetallic couple 34,

. the contact members 32 and 33 being correspondingly arranged, so that the control circuit is completed through each of them at a predetermined temperature.

The modified system shown in Fig.2 differs from that shown in Fig. 1 in that the relay '6 is omitted, relay contact members 39 and 40 being interposed directly in the conductor 5. These contact members 39 and 40 are adapted to be connected by means of a contact member 12, as in the first modification.

In the operation of the foregoing system, the thermostat 34 and its coiiperating coniact members are so proportioned and adjusted that the contact member 35 engages the contact member 32 when the heat of the surrounding medium falls below a predetermined point. Electric connection is thereby established in the control circuit through the contact member 24, armature coil 21, contact member 25, conductors 28 and 29 and coils 30 and 31. The coils 21,

I 30 and 31 are so wound that when the circuit is completed in the manner just described, the armature 17 will be caused to rotate in a counter-clockwise direction about the pivot 14, carrying with it the support 13 and thereby separating the contact members '15 and 16 from the contact members 24 and and bringing the first-named contact members into engagement with the contact members 26 and 27. The same movement of the rod 13 causes the contact member 1 12 to close the solenoid circuit which energizes the relay 6, and current is thereby permitted to flow through the vcurrent-consuming device 1. It will be observedfthat the control circuit which was completed by the engagement of the contact members 32 and 35 has been interrupted, and therefore,

when the thermostat 34 becomes heated and members 15 and 26, conductors 28 and 29,

and coils 30 and 31. Since the current in the coils 30 and 31 is flowing in the same direction as before, while the current in the armature coil 21 is flowing in the re verse direction, the armature core 17 will be caused to rotate in a clockwise direction, thus breakingthe circuit which operates the relay 6 and interrupting the current in the main heating circuit. By this clockwise rotation of the armature core 17, the contact members 15 and 16 are brought again into engagement with the contact members 24 and 25, thus completing the cycle of operations.

It is to be particularly noted that no auxiliary source of low-voltage current supply is necessary in the system described above, the breaking of the control circuit by the oscillating contact members 15 and 16 being sufiiciently rapidto prevent arcing in this circuit.

I The arrangement shown in Fig. 2 may be adopted when the power in the conductor 5 is not sufficiently great to cause destructive arcing between the contact member 12 and the contact members 39 and 40.

While my invention is particularly adaptable to electric heating apparatus, it is to be understood that it may also be employed for regulating other electric circuits in ,pro-

portion to temperature changes. It is also to be understood that my system may be variously modified by persons skilled in .the art to which my invention appertains,

operated by the said thermostat to close the said control circuit, means comprising an oscillatory contact-making wound armature for interrupting the said control circuit while the said contact members are inengagement, a magnet for actuating the said armature and means for reversing the con-' nections for supplying energy to the saidarmature, the said reversing means being operable at each oscillation of the said armature. j

2. A thermostat system for electric circuit control comprising a relay, a control erated by circuit for energizing the said relay, a thermostat, contact members adapted to be opthe said thermostat to close the said control circuit, and means comprising a stationary electromagnet havinga con stant polarity and an oscillatory contactmaking, wound-armature member for interrupting the said .control circuit while the said contact members are in engagement.

8. A thermostat system for electric circuit control comprising arelay, a contactmaking wound armature,'an electromagnet adapted to operate the said armaturea control circuit for energizing the said relay and the said magnet, a. thermostat. cont-actmembers adapted to be operated by the said thermostat to close the said control circuit, and other contact members inthe said control circuit adapted to be operated by the movement of the said relay to open the said control circuit, and to reverse the connections for supplying energy to the said wound armature.

4. A thermostat system for electric circuit control comprising a relay, a control circuit for energizing the said relay, a thermostat, means controlled by the said thermostatfor closing the said control circuit to operate the said relay, and means comprising a stationary electromagnet having a constant polarIt-y and an oscillatory wound armature and contact members associated with the said armature and cooperating with fixed contact members in the said control circuitfor interrupting the said control circuit while the first-named contact members are closed.

5. A thermostat system for electric circuit control comprising a relay contact member, a pivoted support for the said contact member, an armature adapted to oscillate in unison with the said support, a field magnet associated with the said armature, a ther mostat, and means controlled by the said thermostat for causing current to pass through the said armature in one direction at a pretermined temperature and for causing current to pass through the said armature in the opposite direction at another predetermined temperature.

6. A thermostat system for electric circuit control comprising a relay contact member, a pivoted support for the said contact member, an armattire adapted to oscillate in unison with the said support, a field magnet associated with the said armature. contact members secured to the said pivoted support and electrically connected to the terminals of the said armature, a control circuit. opposed pairs of fixed contact members of opposite polarity in the said control circuit adapted to cooperate with the last-named contact members on the said pivoted supnet having a constant port, a thermostat, and means operated by the thermostat for closing the said control circuit at predetermined temperatures.

7. A thermostat system for electric circuit control comprising a stationary electromagnet having a constant polarity, a pivotally mounted arm, an armature carried by said arm having a magnetizing winding, a switch member carried by said arm for effecting the reversal of the connections of said winding, and a second switch member carried by said arm.

8. A thermostat system for electric circuit control comprising a stationary electromagnet having a constant polarity, a pivotally mounted arm, an armature carried by said arm having a magnetizing winding, a switch member carried by said arm for controlling an electrical circuit, and means operable by said arm for effecting the reversal of the connections of said winding upon each operative movement of said arm.

9. A thermostat system for electric circuit control comprising a stationary electromag polarity, av pivotally mounted arm, an armature carried by said arm having a magnetizingwinding, a switch member carried by said arm for efiect-ing the reversal of the connections of said winding. a second switch member carried by said arm, and a thermostat for controlling the circuitof said winding. I 10. A thermostat system for electric circuit control comprising a stationary electromagnet having a constant polarity, a pivotally mounted arm, an armature carried by said arm having a magnetizing windingzh switch member carried by said arm for et-. fecting the reversal of the connections of said winding. a second switch member carried by said arm. a thermostat for controlling the circuit of said winding, said reversing switch member being operable to open the circuits controlled by said thermostat while the latter is in operative position.

11. A thermostat system for electric circuit control comprising astationary electromagnet having a winding adapted to pro-' duce a constant polarity, a pivotallv mounted arm. an armature carried by said arm and having a magnetizing winding as sociated with said electromagnet, a switch member carried by said arm on one side of said armature'winding for efi'ecting the reversal of the connections of said winding, and a second switch member carried by said arm 'on the other side of said armature winding.

In testimony whereof, I have hereunto subscribed my nanlethis 23rd day of Sept,

FRANK THORNTON, JR. Witnesses:

E. LYLE PowELL,

B. B. HISES. 

